Erasing device



J. H. BALDWIN.

ERASING DEVICE.

APPLICATION FILED OCT 26,1918- RENEWED JULY H, 1921.

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2 SHEETS-SHEET I.

ITLUEIICLBF .l. H. BALDWIN.

ERASING DEVICE.

APPLICATION FILED OCT 26.1918- RENEWED JULY 11. 1921.

13%,734. Patented 10mm, 1921.

2 SHEETS-SHEET 2.

Inn/ e @1 65 UNITED STATES JOHN H. BALDWIN, OF CHICAGO, ILLINOIS,

COMPANY, OF CHICAGO, ILLINOIS,

ASSIGNOR 'lTOrTHE BALDWIN ERAC A CORPORATION OF ILLINCIS.

ERASING DEVICE.

Application flled October 26, 1918, Serial No. 259,741. Renewed July 11, 1921.

To all whom it may concern Be it known that I, JoHN H. BALDWIN, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Erasing Devices, of which the following is a specification, and which are illustrated in the accompanying dra\v ings, forming a part thereof.

The invention relates to apparatus for erasing written matter in accordance with the method which forms the subject of Letters Patent No. 1,222,592 issued to me on April 17th, 1917. The object of the invention is to provide improved apparatus for effectually performing the said method of erasing written matter.

The forms of apparatus illustrated in Patent N 0. 1,183,424, issued to me on May 16th, 1916, and in my pending application for patent on erasing attachment for typewriters, Serial No. 249,793 filed August 14th, 1918, perform satisfactory erasures but I have found that improved results are obtaiped with less effort and with greater certainty if provision is made for a progressive engagement of the adhesive body with the written sheet, over the area of contact between the two in all directions from a central point within the said area and for a progressive separation of the sheet and adhesive body inwardly from the periphery. of the said area of contact. The removal of fibers from the surface of the sheet is thus accomplished along converging lines and is wholly confined within the area where the erasure is required. The invention accordingly contemplates that, when a strip of adhesive tape is used as the erasing medium, provision to be made for causing the operative portion of the tape to assume a convex or bulging form. It is also desirable that provision be made for jerking the tape away from the sheet immediately after complete contact has been made between the two regardless of the release of pressure bythe hand. It is further proposed that the foregoing several improvements may, if desired, be incorporated in apparatus which is complete in itself for use either in conjunction with a machine or independently of it and for erasing any form of written or printed matter from any charactor of surface.

In the accompanying drawings Figure 1 is a plane view, partly in sec- Specification of Letters Patent.

Patented Decf13, 1921..

Serial No. 183,946.

tion, showing a form of the improved apparatus arranged for use as a typewriter attachment together with some details of the associated typewriter, the plane of section being indicated by the line 11 on Fig. 2;

Fig. 2 is a central vertical longitudinal sectional view of the apparatus and associated parts shown in Fig. 1, a different position of the movable elements being represented by dotted lines;

Fig. 3 is a detail plan sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a detail perspective view of the form of apparatus illustrated in Figs. 1, 2 and 3.

Fig. 5 is a side elevation partly in section showing a form ofthe device adapted for independent use, and

Figs. 6 and 8 are detail perspective views showing two forms of an elastic stripping plate and Fig. 7 shows a guiding and supporting element which may be used with the different forms of the apparatus.

Whether the device is to be employed as a typewriter attachment or independently therefrom, it may be supplied with winding and supply spools 10, 11, for the adhesive tape 12. The winding and supply spools are accordingly shown in both Figs. 1 and 5. To permit of a spool originally supplied with tape but from which the said supply has been exhausted, being used as the winding spool 10, both the winding spool 10 and supply spool 11 are peripherally provided with ratchet teeth 13, although the feeding and holding pawls, as 1 1, 15 (Fig. 1) or 16, 17, (Fig. 5) cooperate only with the winding spool 10.

In each of the forms of construction illustrated in the drawings, the winding and supply spools 10, 11, are removably held within a case comprising sheet metal wall plates, as 18, 19, (Figs. 1 and 2), although only one of these plates, as 20, is shown in Fig. 5. In each instance the two wall plates of the case are removably connected by spacing posts, 21, 22, which also serve as spindles upon which the spools turn. Separation of the wall plates of the case permits removal and replacement of the spools. The wall plates, as18, 19, or 20, of the case are also formed to provide the case with an open front end indicated at 23 (Fig. 1) and at 24 (Fig. 5) and a supporting and guide roller 25 is held between the plates at the said open front end of the correspondin case, the roller being mounted on a spind e 25 similar to the spacing posts or spindles 21, 22. The adhesive tape 12 extends about the said supporting and guide roller 25 and this guide roller supports the tape for contact with the sheet (not shown) at the place where the erasure is to be made.

In order that the particular portion of the tape 12, which is effective at each operation, will normally assume a bulging form both longitudinally or transversely, the supporting and guide roller 25 is preferably crowned as most clearly shown 1n Flg. 7. The yielding of this roller, or of the support against which the sheet (not shown) is held, is accordin ly relied upon to permit the tape to ma e flat contact with the sheet, while upon removal of the tape from the sheet, the separation between the parts proceeds progressively inwardly from the marginal portions of the area of contact. It will be understood that the hardness of the supporting and guide roller 25 may be varied in different devices for the most satisfactory operation upon the quality of paper from which the erasures are most usually made and also in accordance with the hardness of the support against which the sheet is held. For erasures upon hard paper held against the relatively soft platen, as 26, (Figs. 1 and 2) of a typewriter, the roller 25 may be made of wood or a hard composition. For erasure upon soft paper, or cloth, 0n the other hand, the roller 25 will be desirably made from rubber or like material.

When the device is to be permanently associated with a typewriter as an attachment, as in Figs. 1 to 4, the case comprising the wall plates 18, 19, is slidin 1y mounte upon a swinging support 27. or this purpose one of the wall plates, as 18 of the case is formed with an apertured flange 28 for receiving the said support. The case is additionally held in sliding contact with the said support b means of a headed stud 29 which is carrie by the support and runs in a slot 30 formed in the wall plate 18. As shown, the support 27 is formed at one end with a hub 31, which turns upon one of the transverse frame members, as 32, of the typewriter and is held against longitudinal displacement thereon by collars 33, 34, the said collars being fixed upon the frame member 32 at opposite sides of the hub 31, by means of pins 33', 34'. The collars are preferably formed on the ends of the arms of a bracket 46, which is secured against a rigid part of the typewriter frame, as the scale bar 47. Under these circumstances, the support 27 and the case which it carries normally hang in the position indicated by dotted lines in Fig. 2 where they are out of the path of movement of the type bars of the typewriter. To insure the return of the support 27 to this position after each operation a spring 35 is carried by the typewriter frame member 32 adjacent one of the collars, as 33, and reacts upon the sup ort 27.

S iding movement of the case comprising the walls plates 18, 19, upon the support 27 is preferably controlled by a spring 36. This spring is principally relied upon for separating the adhesive tape 12 from the sheet (not shown) by a quick movement at each operation. As shown, the spring 36 reacts between the depending flange 28 of the wall plate 18 and a depending flange 37 at the free end of swinging support 27. Preferably the swinging support 27 is also provided with an outwardly projectin flange 38 at its free end for engagement wit% the underside of the type-bar guide 39 of the typewriter to limit the swinging movement of the support in one direction. As the type-bar guide 39 is customarily forked, as shown in Fig. 1, a depending stud 40 may be carried by the bottom wall plate 18 of the case for entering the space 41 between the arms of the forked type-bar guide 39 to guide the movement of the case as it approaches the end of its forward stroke. An accurate register of the adhesive tape 12 with the place where the erasure is to be made is thusinsured. To accommodate the stud 40 as the case approaches its rearward position upon the swinging support 27, the said support is preferably slotted at its forward end, as at 40 (Fig. 2).

A plun or 42 serves both for swinging the sup ort 2 upwardly against the underside of t e type-bar guide 39 and for advancing the tape holding case upon the said support when the latter has been brought to the horizontal osition illustrated by full lines in Fig. 2. referably these two operations occur successively during a single inthrust of the plunger 42. Furthermore, in order that the spring 36 may effect a quick and forceful separation of the adhesive tape from the sheet upon which the erasure is made, independently of the plunger 42, the present construction provides for an automatic disconnection of the ta e-holding case from the plunger as the tapeiolding case approaches the limit of its forward movement.

The plunger 42 is conveniently supported in a horizontal position above the typewriter key-board (not shown) by being formed with a tubular stem 43 which telescopes upon a horizontal fixed tubular post 44. Under these circumstances the plunger retracting spring 45 is housed within the bores of the plunger stem and post. The post 44 is in turn supported by eing mounted upon the bracket 46.

The operative part of the plunger 42 comprises a yoke 48 which is rigidly connected with the stem 43 and the arms 49, 50. of this yoke extend through and beyond the bracket 46 with which they have sliding engagement. A horizontally swinging pawl 51 controlled by a spring 52 is pivotally mounted upon the inner end of each arm 49, 50, of the yoke 48. These pawls normally occupy the inclined positions illustrated in Fig. 1. In this position of the pawls they serve to engage an outwardly projecting portion 54 of the flange 28 when the support 27 has been raised to the horizontal position. Continued inward movement of the plunger 42 accordingly serves to force the adhesive tape 12 against the sheet from which the erasure is to be made. As the plunger 42 reaches the limit of its inward movement the pawls 51 are separated to permit the flange 28 to pass between them as the tape carrying case is re turned by the spring 36.

Separation of the pawls 51 is accomplished through the medium of. a pair of links 55, one of which is connected to each pawl for swinging it upon its pivot. As shown, each link 55 is held against the under side of the bracket 46 by a stud 56 (Fig. 4). To permit limited sliding movement of the links 55, each stud 56 extends through a slotted opening 57 in the corresponding link. If desired the amount of movement permitted in each of the links 55 may be adjusted by the use of a set screw 58 which enters the corresponding slotted opening 57 through the adjacent end of the link and serves as a stop for engagement with the stud 56. It follows that during the greater part of the inward travel of the plunger 42, the links 55 slide upon the studs 56 and the pawls 51 are retained in the inclined positions indicated in Fig. 1 by their springs 52. As the plunger 42 approaches the limit of its inward movement, further travel of the links 55 is prevented, as by the engagement of the set screws 58 with the studs 56. The pawls 51 accordingly move outwardly and become disengaged from the flange 28.

Movement of the swinging support 27 and the part-s carried thereby from the position indicated by dotted lines in Fig. 2 to the horizontal position preferably occurs during the initial inward movement of the plunger 42. For this purpose, each of the arms 49, 50, of the yoke 48 is formed with a cam engaging shoulder 59 and these arms cotiperate with cams 60 formed on the hub 31 at its opposite ends. Engagement of the shoulders 59 with projecting portions 61 of the corresponding cams serves to swing the sup port 27 upwardly. Thereafter the project-- mg portions of the cams 61 ride upon the arms 49, 50, of the yoke 48 for maintaining the support 27 in its elevated position.

It will be understood that in the form of construction in Figs. 1 to 4, the feeding pawl 14 is fixed upon the swinging support 27 and forward movement of the tape-holding case upon the swinging support 27. In the form of construction illustrated in Fig. 5, the feeding pawl 16 is mounted upon the shaft 62 of a movable handle 63. As shown, the shaft 62 of the handle 63 extends into asocket 64 centrallv formed upon the inside of the wall plate 20 and reacts upon the lower end of the said socket through a spring 65; It follows that when the handle 63 is used for forcing the corresponding adhesive tape 12 upon the sheet, compression of the spring 65 permits sufficient movement of the feeding pawl 16 to turn the winding spool 10 for presenting a fresh portion of the adhesive tape 12 in front of the guiding and supporting roller 25.

In some instances, particularly when the device is constructed to be held in thehand, as in Fig. 5, it is desirable to provide a yielding stripper plate 66 in front of the guiding and supporting roller 25. This stripper plate is apertured. as at 67 (Fig. 6) or notched, as at 70, (Fig. 8) to permit the guiding and supporting roller 25 and the associated part of the adhesive tape 12 to operate through the same and it is preferably formed of resilient material. The stripper plate 66 is also shown as being used upon the form of apparatus illustrated in Figs. 1 to 4, and in each case it is held in place by being formed with bifurcated curved ends 68. 69, the two arms of each of which straddle the roller 25 and are connected to the spindle of the roller at opposite sides of the same. The stripper plate 66 of course engages the sheet from which the erasure is to be made in advance of the engagement therewith of the adhesive tape 12, this latter being permitted by the yielding of the curved end portions 68, 69 of the plate. The stripper serves to hold the sheet firmly against its support at the place where the erasure is to be made and it assists in accurately locating the engagement of the adhesive tape with the sheet at the desired place. It also insures that the abrasion of the sheet caused by the removal of its surface fibers will be confined to that part of the sheet which is exposed through the opening, as 67, in the stripper plate. The resilience of the stripper plate and its curved end portions 68, 69, also aids in the separation of the adhesive tape from the sheet by a quick movement upon release of pressure upon the handle 63 (Fig. 5) or upon the disengagement of the pawls 51 from the flange 28 (Fig. 1.)

I claim as my invention:

1. In an erasing device, in combination, a spool carrying frame, a guiding and supporting roller of yielding material mounted 'at the forward end of the frame, and winding and supply spools mounted in the frame for feeding an adhesive tape over the said guiding and supporting roller.

2. In an erasing device, in combination, a spool carrying frame, a crowned guiding and supporting roller of yielding material mounted at the forward end of the frame, and winding and Supply spools mounted in the frame for feeding an adhesive tape over the said guiding and supporting roller.

3. In an erasing device, in combination, a spool carrying frame, a guiding and supporting roller of yielding material mounted at the forward end of the frame, winding and supply spools mounted in the frame for feeding an adhesive tape over the said guiding and supporting roller, and a yielding stri per plate mounted in front of the said gui ing and supporting roller.

4. In an erasing device, in combination, a slidingly mounted member having an adhesive contact face, a retracting spring therefor, a reciprocable plunger for advancing the member and means pivotally attached to said plunger for disengaging the plunger from the said member by a lateral movement of said means as the said member reaches the limit of its forward travel.

5. In an erasing device, in combination, a reciprocable member having an adhesive contact face, a retracting spring therefor, a reciprocable actuating plunger having a laterally swinging pawl at its forward end for engagement with the said member and means operable when the said member reaches the limit of its forward movement for swinging the pawl out of engagement with the said member to permit return movement of the said member independent of the plunger.

6. In an erasing device, in combination, a reciprocable member having an adhesive contact face, a reciprocable actuating plunger, a laterally swinging pawl mounted upon the forward-end of the plunger for engagement with the said member in one position of the pawl, the pawl and plunger being both clear of the path of movement of the said member when the awl occupies a different position, and a link connected to the pawl and having limited sliding movement less than the range of movement of the plunger.

7-. In an erasing device, in combination, a swinging support, a member having an adhesive contact face slidingly mounted on the said support and a reciprocable plunger operable successively during a single stroke in one direction to swing the said support and slide the said member thereon.

S. In an erasing device, in combination, a swinging support, a member having an adhesive contact face slidingly mounted upon the said support, a reciprocable plunger operable during a part of its stroke in one direction to swing the said support, a laterally swinging pawl carried by the plunger for engagement with the said member in one position of the pawl to advance the said member upon the support during the remainder of the said stroke of the plunger. the pawl and plunger being both clear of the path of movement of the said member when the pawl occupies a different sition, means for swinging the pawl w en the plunger reaches the end of its said stroke, and a spring for retracting the said member upon the support.

9. In an erasing device, in combination, a reciprocable member having an adhesive contact face, a retracting spring therefor, actuating means for advancing the said member and means for releasing the actuating means from the said member at the end of its forward movement to permit independent return movement of the same b its s rin y p g JOHN H. BALDWIN. 

